Vacuum head for filling containers with powders



VACUUM HEAD FOR FILLING CONTAINERS WITH POWDERS June 27, 1950 c. F. CARTER Filed Sept. 25, 1946 r II N Fla. 2

IN V EN TOR. C'L Anna E 63mm: BY lzwfiot &, ail/MW Arromu-Ya FIG. 1

Patented June 27, 1950 VACUUM HEAD FOR FILLING CONTAINERS WITH PQWDERS Clarence F. Carter, Danville, Ill.

Application September 23, 1946, Serial'No. 698,605

This invention relates to an apparatus for filling collapsible containers with comminuted solids. More particularly it relates to'a new filling head and shroud which can be used with a machine such as that described in my United.

States Patent 2,360,198, especially for filling boxes, cartons, bags or other containers which have folding flaps as a closure means, or which must be supported in filling position.

It is an object of the invention to provide an improved filling head by which collapsible containers closed by folding flaps, are guided into filling position in a shrouded filling head with the flaps held so that they do not interfere with the filling operation, the container being gripped by an inflated means to form an air tight seal or joint near the top at about the level to which the container is to be filled.

It is a further object of the invention to pro- Vide a means for firmly gripping the container near the open top forming an air tight joint around its entire periphery while it is held in filling position, in order that the pressure may be changed equally and simultaneously inside and outside the container.

It is a further object to provide an improve ment in a machine for filling containers with solid particles by creating a vacuum in and around the container, the improvement comprising a member having a part adapted to fit loosely inside the open top of a container, another member spaced therefrom to fit loosely around the outside of said container, said parts forming an opening to receive the container closure means and a limited portion of the side walls, and means joint around the top of the container. This permits the shroud and the inside of the container to be evacuated without leakage of air around the top of the container.

In the case of rigid containers, such as metal cans, closed by a separate lid, there is usually no need for the shroud, and the top of the can is usually held firmly against a resilient ring of suitable contour which effectively seals it from 5 Claims. (Cl. 226-116) atmospheric leaks when in filling position. There are no fiaps to interfere, and the can is stron enough to withstand the pressure differential. Even with certain collapsible containers having a separate lid, the same type of device, with the shroud added, can be used as is shown in the above mentioned patent.

However bags and boxes closed by flaps or by folding the open end or which are too fragile to Withstand pressing against a resilient ring, cannot be handled in this way, either because the container is not rigid enough to be pressed sufficiently hard against the sealing ring to form the air tight joint necessary to accomplish the filling operation, or because the flaps interfere.

The present invention permits the air tight joint to be formed by means of a, tube which, by inflating it, can be brought to bear against the periphery of the container adjacent the top, either inside or outside, so as to press the container against a supporting lip or edge of the filling head or shroud, thereby forming the desired air tight joint.

In one specific embodiment the invention comprises an improved filling device for vacuum type machines for fillin containers with comminuted solid, which comprises a vacuum filling head having an opening into a hopper, a pair of screened openings adjacent the hopper opening, said screened openings connecting with ducts for withdrawing and admitting air, a flanged throat piece adapted to fit inside a container to be filled, closure-guide members attached thereto, a

part of said head adapted to fit around the outside of the container, said last mentioned part and said throat piece forming an opening conforming in shape and size to the outline of the vessel to permit entrance of the closure flaps and to permit limited egress of the top of the container, when in filling position, means operable to close said opening, and a vacuum shroud adapted to surround a container when in filling position, said shroud being closable by containerlifting means forming a part of the machine.

Referring to the drawings,

Figure 1 represents a side view partly in section of the filling head.

Figure 2 is a plan view in section along the lines 2-2 of Figure 1.

Figure 3 is another embodiment of the invention partly in section.

Figure 4 is a plan view in section along the lines 4-4 of Figure 3.

Referring to Figure 1, a lifting platform It] is provided, preferably having a resilient ring ll around the outer rim thereof. The lifter may be actuated in a manner illustrated in the above mentioned Patent 2,360,198.

A container, I2, is placed upon the lifting platform I9 which can then be elevated by a suitable means until the container is in filling position within the shroud l3. A rubber skirt or flap l4 around the bottom of the flared shroud l3 rests against resilient ring II forming a continuous seal, thereby completely housing the container |2 within the shroud and preventing leakage of air when the shroud is evacuated. The shroud may be evacuated through line 115 which leads to a source of vacuum not shown. The head as illustrated is used in conjunction with a rectangular pasteboard carton having the usual folding closure flaps l6 and I9, there being two short flaps on each end and two flaps on each side which fold in and overlap to close the box. The height of the shroud is such that when the lifting platform It is'in position the flaps extend into the closurerece'iving openings between the .fianged inner throat-25 of the filling head and the outer shroud and support '23 and 2 1. The filling head shown in-Figure 1 comprises a hopper H contain-ing the powder. The hopper opens directly to the interior of the carton when it is in filling position. The hopper can be movable, for example rotatable, and can have a plurality of similar .heads depending therefrom. The head comprises a body 18 to which the hopper is fastened by conventional means, not shown, such as cap screws or the like. Openings are provided in the body it of the head for vacuum ducts |-9 .and 20 leading to chamber 2-2, the outlet of which is covered by a screen 2|, forming one division of the filling head. There is another division in the head on the left hand side corresponding to this one. This is similar to the device illustratedin Figure '3,-attention being called to-chambers 49-, ll ,lines 38, 3'9 and screens #2, 43. Shroud supports 23 form the meansofassembling body 9 with shroud l3 which has a flange 24 for thispurpose. This part fits around the outside of the container l2.

Attached to the body M3 by means of screws '25 through a flush fitting lip is a flanged piece -2'6 forming a threat fitting :loosely inside the open end of the container 12. The throat piece extends into container 12 a distance of about to inch, suiiicient for it to be gripped by member 28 which is operable to close the opening formed by the throat piece and part of the head and shroud fitting outside the container. Depending from the throat *piece 26 and sloping inwardly-are guides 21. These serve to spread flaps l6 and and to guide them into the .closure receiviing opening just described, and to guide the open end of the container I2 into position around throat piece 26, as the lifting plate raises the container l2 into filling position. The lower part of the throat piece fits just inside the :open top below the point at which the vflaps 1-6 and I join the box.

The throat piece 26 alsoserves to clamp screen 2| into place. The screen is cut slightly larger than the throat to cover the entire area inside the throat. The screen is held in place between a downwardly extending lip of body L8 and the flanged edge of member 26. A portion of the screen is cut away to correspond to the opening of hopper I! through body l8, this opening usually being circular. The lower endofthe body l8 forming this opening from hopper 'IJ 2is tapered outwardly. A male insert 3| fits inside this-open- 'ingand is flared at the end to correspond to the taper, so as to grip the screen 2| and hold it in place. Insert 3| is held in place by any suitable means. The screen 2| thus is held firmly over the lower end of chamber 22 and prevents powder from entering the passage way and duct l9 when the latter is evacuated. At the same time powder can flow from hopper into the container without interference when the interior is evacuated through chamber 2-2 and duct 9. The top of shroud I3 is flanged as indicated at 24. In the embodiment shown in Figures 1 and 2, a groove or channel is cut in flange 24 to receive expandable tube '28 which is made of rubber, synthetic rubber or other elastomer. The channel is preferably semi-circular in cross section. The rubber tube is continuous around the inside of the boss or flange 24 except for an outlet 29 through which compressed air can be introduced and allowed to escape. The outlet 29 is enclosed within a pipe 30 leading into boss 24 from a source of compressed air which when admitted, expands the tube 28 thus closing the closure-receiving opening. Thus, when the box I12 is in filling position, compressed air is introduced through pipe at and inlet tube 29 into the rubber 'tube 28 causingit to expandand press against the upper portion of the open top of the box l2 which in turn presses against thezinside edge of the throat piece 26, thus forming an :air tightjoint preventing air being drawn either into the shroud or the inside of the box when :vacuum is supplied. 'The shroud is closed at the bottom by lift platform 10 as described. The .air can be withdrawn from the shroud around the exterior .of the box through duct 15 at the same timeitis withdrawn .from the interior of the :box through .screenedhead 121., passage 22 and duct 9. Ducts l5 and 9 are attached to a source of vacuum :so that the pressure inside and outside the box is about the same at all times. Becauseof the difference in pressure .between the interior of the .box and on the powder in the hopper, the'powder is drawn "through duct i! into the box |2. In this manner the box is filled to capacity.

The preferred operation is carried out withdrawing air from first .oneside and then the other of the divided filling #head with n interval between in which the pressure is restored to atmospheric by allowing air 'to now back through the duct which has been evacuated, thus clearing the screen ofxpowder that may have been accumulated thereon. By-alternating the evacuation and relief of pressure between the heads, :a rapid-and uniiorm filling operation isLaccomplished.

When the filling is complete, pressure .is r.e-

stored to normal both in box 1.2 :and shroud l3.

Expanded tube .28 is deflated ithus releasing its grip on the box. lzift plate vlilzis lowered, removing the box from filling position. .It is then removed from the lift plate, and replaced by an empty container and the operation is repeated.

The ffilled .box closed :and sealed by suitable means.

Figure 3 illustrates a modification in which the expandable tube is in the flanged throat member and closes *the closure-passage by expanding outwardly against the inside of the open top of the container which in turn is thrust against flange .24, thereby sealing it in such a way that it can be evacuated in a manner .described above in connection with Figures 1 .and 2. The body |-8 contains compartments '49 and 4| connected with ducts .38 and 39 connected with a source of vacuum. These compartments are covered-by screens 42 and '43 held 'in position by member 3| and the flanged edge of throat piece 32 which is fastened to the body [8 in a manner similar to that previously described in connection with Figure 1. The flap or closureguides 33, are similar to guides 21 shown in Figures 1 and 2. A channel or groove is out around the exterior portion of throat piece 32, running circumferentially and parallel with the sides of the container, into which an expandable tube 34 fits. An outlet tube 35 extends through a vertical passage 36 drilled in the throat piece 32 and extending into body I8. This passage opens into a duct 31 connected with a source of compressed air. Vacuum ducts 33 and 39 lead into passages 4t and 4| within head I8 and these in turn, communicate with the screened openings 42 and 43 through which the air contained within container 12 may be withdrawn by the use of an appropriate valving system. In operation the lifting plate 10 thrusts the container 12 upward and the flaps of the container slide along the guide prongs 33 into the fiapor closure-receiving passageway between the throat piece 32 and body 18 on the one side and flange 24 on the other. Compressed air is introduced through duct 31 and causes tube 34 to expand and press the upper lip of the container against the shroud, thereby sealing it. By evacuating the container alternately through screens 42 and 43 and at the same time evacuating the shroud through line 15, powder is caused to flow through duct l'l into the interior of the container. The screens are cleared as above described.

The flanged member 24 and support 23 can be integral with body It, and shroud I3 can be attached thereto.

The rubber members 28 can .be actuated by cams, for example to press against the sides of the container and fill the opening. Expandable members 28 and 34 can be combined in one head.

In order to prevent certain types of containers from bulging due to slight differences in pressure inside and outside the container, fins l3 may be provided. These also aid in guiding the container into position. The preferred embodiments of my invention are described but it should be understood that modification thereof within the scope of one skilled in the art may come within its scope.

I claim as my invention:

1. A filling head for vacuum type machines adapted to fill containers with powdered solids, which comprises means for attaching said head, to a hopper, a, body having a central opening for passing powder from said hopper into a container when the latter is in filling position with relation to said head, a first screened opening in said body, a second screened opening in said body, ducts connecting said screened openings with a source of reduced pressure, a throat piece adapted to fit loosely inside a container to be filled, said throat piece comprising guide members for guiding said container into position around said throat piece, a member spaced from said throat piece and lying around it thereby forming an opening adapted to receive the closure means of said container and a limited portion of its side walls, an inflatable member adapted when inflated to press against the portion of said container Within said opening thereby forming an air tight joint, a shroud, means for attaching said shroud to the filling head, means for attaching said shroud to a source of vacuum, and means on said shroud engageable with a lift plate of the filling machine when said container is in filling position to form an air tight joint.

2. A filling head for vacuum type machines adapted to fill containers with comminuted solids, which comprises means for attaching said head to a hopper, a body having an opening for passing comminuted solids from said hopper into a container when the latter is in filling position with relation to said head, a screened opening in said body, ducts connecting said screened opening with a source of reduced pressure, a throat piece adapted to fit loosely inside a container to be filled, an annular member spaced from said throat piece defining an opening adapted to receive the closure means of said container and a limited portion of its side Walls, an expandable member adapted when expanded to press against the portion of said container within said opening, thereby forming a vacuum tight joint, a shroud, means for engaging said shroud and said filling head, means for attaching said shroud to a source of vacuum, and means on said shroud engageable with a container lift plate of the filling machine forming a vacuum tight joint when a container is in filling position.

3. The apparatus of claim 2 wherein the expandable member is incorporated in said throat piece.

4. The apparatus of claim 2 wherein the expandable member is incorporated in said annular member.

5. The apparatus of claim 2 wherein the shroud comprises container positioning guides.

CLARENCE F. CARTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,007,358 Joplin Oct. 31, 1911 1,978,913 Ricci Oct. 30, 1934 2,126,163 Young et a1. Aug. 9, 1938 2,170,469 Carter .Aug. 22, 1939 2,178,494 Richardson Oct. 31, 1939 2,262,620 Neuman Nov. 11, 1941 2,322,090 Hobbie June 15, 1943 FOREIGN PATENTS Number Country Date 492,560 France Mar. 25, 1919 

